The overlying goal of this project is to determine how neural activity is integrated between the somatosensory cortices to form a unified percept of a bilateral, tactile stimulus. As recent evidence shows that the somatosensory cortices are responsive to bilateral stimuli, the rat somatosensory system is used here as a model system in studying intercortical integration. However, little is know about the interactions of neural activity between these cortical areas and the behavioral significance of sensory percepts that these interactions are thought to underlie. To address the nature of intercortical integration, multi-electrode arrays chronically implanted into both somatosensory cortices will allow ensembles of single unit recordings to be made while the spatial and temporal aspects of bilateral whisker stimuli in both anesthitized and awake, behaving rats is parametrically varied. In Specific AIM I, neuronal responses to bilateral stimuli in the anesthitized rat will be used to make predictions tested in the Specific AIM II regarding the behavioral performance of rats trained in bilateral tactile discrimination tasks. By combining multi-site recordings with behavioral tasks that necessitate the cooperativity of both cortices, we will be able to correlate ensemble activity to the psychophysical performance of the animal.